Add cancellation reason tracking with user/system codes and UI

internal/syncengine/queue.go

@@ -13,8 +13,9 @@ type Queue struct {
 }
 
 type RunInfo struct {
-	JobID   int64
-	Cancel  func()
+	JobID  int64
+	Cancel func()
+	ByUser bool
 }
 
 func NewQueue() *Queue {
@@ -54,10 +55,18 @@ func (q *Queue) GetJobID(syncPairID int64) (int64, bool) {
 	return info.JobID, true
 }
 
-func (q *Queue) Cancel(syncPairID int64) {
+func (q *Queue) Cancel(syncPairID int64, byUser bool) {
 	q.mu.Lock()
 	defer q.mu.Unlock()
 	if info, exists := q.runs[syncPairID]; exists && info.Cancel != nil {
+		info.ByUser = byUser
 		info.Cancel()
 	}
 }
+
+func (q *Queue) IsCancelledByUser(syncPairID int64) bool {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	info, exists := q.runs[syncPairID]
+	return exists && info.ByUser
+}